Obstructive jaundice expands intrahepatic regulatory T cells, which impair liver T lymphocyte function but modulate liver cholestasis and fibrosis

Causal association between 731 immunocyte phenotypes and liver cirrhosis: A bidirectional two-sample mendelian randomization analysis

BACKGROUND

Liver cirrhosis is a progressive hepatic disease whose immunological basis has attracted increasing attention. However, it remains unclear whether a concrete causal association exists between immunocyte phenotypes and liver cirrhosis.

AIM

To explore the concrete causal relationships between immunocyte phenotypes and liver cirrhosis through a mendelian randomization (MR) study.

METHODS

Data on 731 immunocyte phenotypes were obtained from genome-wide association studies. Liver cirrhosis data were derived from the Finn Gen dataset, which included 214403 individuals of European ancestry. We used inverse variable weighting as the primary analysis method to assess the causal relationship. Sensitivity analyses were conducted to evaluate heterogeneity and horizontal pleiotropy.

RESULTS

The MR analysis demonstrated that 11 immune cell phenotypes have a positive association with liver cirrhosis [P < 0.05, odds ratio (OR) > 1] and that 9 immunocyte phenotypes were negatively correlated with liver cirrhosis (P < 0.05, OR < 1). Liver cirrhosis was positively linked to 9 immune cell phenotypes (P < 0.05, OR > 1) and negatively linked to 10 immune cell phenotypes (P < 0.05; OR < 1). None of these associations showed heterogeneity or horizontally pleiotropy (P > 0.05).

CONCLUSION

This bidirectional two-sample MR study demonstrated a concrete causal association between immunocyte phenotypes and liver cirrhosis. These findings offer new directions for the treatment of liver cirrhosis.

Immune system dysregulation in the pathogenesis of non-alcoholic steatohepatitis: unveiling the critical role of T and B lymphocytes

Non-alcoholic fatty liver disease (NAFLD), characterized by the excessive accumulation of fat within the cytoplasm of hepatocytes (exceeding 5% of liver weight) in individuals without significant alcohol consumption, has rapidly evolved into a pressing global health issue, affecting approximately 25% of the world population. This condition, closely associated with obesity, type 2 diabetes, and the metabolic syndrome, encompasses a spectrum of liver disorders ranging from simple steatosis without inflammation to non-alcoholic steatohepatitis (NASH) and cirrhotic liver disease. Recent research has illuminated the complex interplay between metabolic and immune responses in the pathogenesis of NASH, underscoring the critical role played by T and B lymphocytes. These immune cells not only contribute to necroinflammatory changes in hepatic lobules but may also drive the onset and progression of liver fibrosis. This narrative review aims to provide a comprehensive exploration of the effector mechanisms employed by T cells, B cells, and their respective subpopulations in the pathogenesis of NASH. Understanding the immunological complexity of NASH holds profound implications for the development of targeted immunotherapeutic strategies to combat this increasingly prevalent and burdensome metabolic liver disease.

Crosstalk of ubiquitin system and non-coding RNA in fibrosis

Chronic tissue injury triggers changes in the cell type and microenvironment at the site of injury and eventually fibrosis develops. Current research suggests that fibrosis is a highly dynamic and reversible process, which means that human intervention after fibrosis has occurred has the potential to slow down or cure fibrosis. The ubiquitin system regulates the biological functions of specific proteins involved in the development of fibrosis, and researchers have designed small molecule drugs to treat fibrotic diseases on this basis, but their therapeutic effects are still limited. With the development of molecular biology technology, researchers have found that non-coding RNA (ncRNA) can interact with the ubiquitin system to jointly regulate the development of fibrosis. More in-depth explorations of the interaction between ncRNA and ubiquitin system will provide new ideas for the clinical treatment of fibrotic diseases.

The Role of CD4+T Cells in Nonalcoholic Steatohepatitis and Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) has become the fourth leading cause of cancer-related deaths worldwide; annually, approximately 830,000 deaths related to liver cancer are diagnosed globally. Since early-stage HCC is clinically asymptomatic, traditional treatment modalities, including surgical ablation, are usually not applicable or result in recurrence. Immunotherapy, particularly immune checkpoint blockade (ICB), provides new hope for cancer therapy; however, immune evasion mechanisms counteract its efficiency. In addition to viral exposure and alcohol addiction, nonalcoholic steatohepatitis (NASH) has become a major cause of HCC. Owing to NASH-related aberrant T cell activation causing tissue damage that leads to impaired immune surveillance, NASH-associated HCC patients respond much less efficiently to ICB treatment than do patients with other etiologies. In addition, abnormal inflammation contributes to NASH progression and NASH-HCC transition, as well as to HCC immune evasion. Therefore, uncovering the detailed mechanism governing how NASH-associated immune cells contribute to NASH progression would benefit HCC prevention and improve HCC immunotherapy efficiency. In the following review, we focused our attention on summarizing the current knowledge of the role of CD4+T cells in NASH and HCC progression, and discuss potential therapeutic strategies involving the targeting of CD4+T cells for the treatment of NASH and HCC.

Treg-tissue cell interactions in repair and regeneration

Regulatory T (Treg) cells are classically known for their critical immunosuppressive functions that support peripheral tolerance. More recent work has demonstrated that Treg cells produce pro-repair mediators independent of their immunosuppressive function, a process that is critical to repair and regeneration in response to numerous tissue insults. These factors act on resident parenchymal and structural cells to initiate repair in a tissue-specific context. This review examines interactions between Treg cells and tissue-resident non-immune cells-in the context of tissue repair, fibrosis, and cancer-and discusses areas for future exploration.

Delivery technologies for therapeutic targeting of fibronectin in autoimmunity and fibrosis applications

Fibronectin (FN) is a critical component of the extracellular matrix (ECM) contributing to various physiological processes, including tissue repair and immune response regulation. FN regulates various cellular functions such as adhesion, proliferation, migration, differentiation, and cytokine release. Alterations in FN expression, deposition, and molecular structure can profoundly impact its interaction with other ECM proteins, growth factors, cells, and associated signaling pathways, thus influencing the progress of diseases such as fibrosis and autoimmune disorders. Therefore, developing therapeutics that directly target FN or its interaction with cells and other ECM components can be an intriguing approach to address autoimmune and fibrosis pathogenesis.

Amphiregulin from regulatory T cells promotes liver fibrosis and insulin resistance in non-alcoholic steatohepatitis

Production of amphiregulin (Areg) by regulatory T (Treg) cells promotes repair after acute tissue injury. Here, we examined the function of Treg cells in non-alcoholic steatohepatitis (NASH), a setting of chronic liver injury. Areg-producing Treg cells were enriched in the livers of mice and humans with NASH. Deletion of Areg in Treg cells, but not in myeloid cells, reduced NASH-induced liver fibrosis. Chronic liver damage induced transcriptional changes associated with Treg cell activation. Mechanistically, Treg cell-derived Areg activated pro-fibrotic transcriptional programs in hepatic stellate cells via epidermal growth factor receptor (EGFR) signaling. Deletion of Areg in Treg cells protected mice from NASH-dependent glucose intolerance, which also was dependent on EGFR signaling on hepatic stellate cells. Areg from Treg cells promoted hepatocyte gluconeogenesis through hepatocyte detection of hepatic stellate cell-derived interleukin-6. Our findings reveal a maladaptive role for Treg cell-mediated tissue repair functions in chronic liver disease and link liver damage to NASH-dependent glucose intolerance.

Integrated analysis reveals crosstalk between pyroptosis and immune regulation in renal fibrosis

Purpose

The pathogenesis of renal fibrosis (RF) involves intricate interactions between profibrotic processes and immune responses. This study aimed to explore the potential involvement of the pyroptosis signaling pathway in immune microenvironment regulation within the context of RF. Through comprehensive bioinformatics analysis and experimental validation, we investigated the influence of pyroptosis on the immune landscape in RF.

Methods

We obtained RNA-seq datasets from Gene Expression Omnibus (GEO) databases and identified Pyroptosis-Associated Regulators (PARs) through literature reviews. Systematic evaluation of alterations in 27 PARs was performed in RF and normal kidney samples, followed by relevant functional analyses. Unsupervised cluster analysis revealed distinct pyroptosis modification patterns. Using single-sample gene set enrichment analysis (ssGSEA), we examined the correlation between pyroptosis and immune infiltration. Hub regulators were identified via weighted gene coexpression network analysis (WGCNA) and further validated in a single-cell RNA-seq dataset. We also established a unilateral ureteral obstruction-induced RF mouse model to verify the expression of key regulators at the mRNA and protein levels.

Results

Our comprehensive analysis revealed altered expression of 19 PARs in RF samples compared to normal samples. Five hub regulators, namely PYCARD, CASP1, AIM2, NOD2, and CASP9, exhibited potential as biomarkers for RF. Based on these regulators, a classifier capable of distinguishing normal samples from RF samples was developed. Furthermore, we identified correlations between immune features and PARs expression, with PYCARD positively associated with regulatory T cells abundance in fibrotic tissues. Unsupervised clustering of RF samples yielded two distinct subtypes (Subtype A and Subtype B), with Subtype B characterized by active immune responses against RF. Subsequent WGCNA analysis identified PYCARD, CASP1, and NOD2 as hub PARs in the pyroptosis modification patterns. Single-cell level validation confirmed PYCARD expression in myofibroblasts, implicating its significance in the stress response of myofibroblasts to injury. In vivo experimental validation further demonstrated elevated PYCARD expression in RF, accompanied by infiltration of Foxp3+ regulatory T cells.

Conclusions

Our findings suggest that pyroptosis plays a pivotal role in orchestrating the immune microenvironment of RF. This study provides valuable insights into the pathogenesis of RF and highlights potential targets for future therapeutic interventions.

Triptolide attenuates CCL4-induced liver fibrosis by regulating the differentiation of CD4+ T cells in mice

Liver fibrosis is a major global health issue, and immune dysregulation is a main contributor. Triptolide is a natural immunosuppressive agent with demonstrated effectiveness in ameliorating liver fibrosis, but whether it exerts anti-liver fibrotic effects via immunoregulation remains obscure. In this study, first, by employing a CCL4-induced liver fibrosis mouse model, we demonstrated that triptolide could alleviate pathological damage to liver tissue and attenuate liver function damaged by CCL4. In addition, triptolide inhibited the expression of liver fibrotic markers such as hydroxyproline, collagen type IV, hyaluronidase, laminin, and procollagen type III, and the protein expression of α-SMA in CCL4-induced liver fibrosis. Second, with the help of network pharmacology, we predicted that triptolide's anti-liver fibrotic effects might occur through the regulation of Th17, Th1, and Th2 cell differentiation, which indicated that triptolide might mitigate liver fibrosis via immunoregulation. Finally, multiplex immunoassays and flow cytometry were adopted to verify this prediction. The results suggested that triptolide could reverse the aberrant expression of inflammatory cytokines caused by CCL4 and regulate the differentiation of Th1, Th2, Th17, and Treg cells. In conclusion, triptolide could attenuate CCL4-induced liver fibrosis by regulating the differentiation of CD4+ T cells. The results obtained in this study extended the application of triptolide and introduced a new mechanism of triptolide's anti-liver fibrotic effects.

Frequency of infiltrating regulatory T-cells in the portal tract of biliary atresia

PURPOSE

Immunological abnormalities have been hypothesized as a pathogenesis of biliary atresia (BA). We previously investigated the frequency and function of circulating regulatory T-cells (Tregs) and reported no differences compared to controls. However, the local Treg profile remains uncertain. We aimed to investigate the frequency of Tregs in BA liver tissues.

METHODS

The number of lymphocytes, CD4+ cells, and CD4+FOXP3+ Tregs infiltrating the portal tract and the percentage of Tregs among CD4+ cells of BA and control patients were visually counted. The correlation between these data and clinical indicators was also examined.

RESULTS

The number of lymphocytes, CD4+ cells, and CD4+FOXP3+ Tregs was higher in the BA group. However, the percentage of Tregs among CD4+ cells was similar in both groups. Each parameter was correlated with serum γ-GTP, but there was no clear association with liver fibrosis, jaundice clearance, and native liver survival.

CONCLUSION

The number of Tregs infiltrating the portal tract was higher in BA patients. However, the infiltration of lymphocytes was also generally increased. Tregs appear to be unsuccessful in suppressing progressive inflammation in BA patients, despite recruitment to local sites. Investigation of Treg function in the local environment is warranted.

Regulatory T cells (Tregs) in liver fibrosis

The ability of the human liver to both synthesize extracellular matrix(ECM), as well as regulate fibrogenesis, are integral functions to maintaining homoeostasis. Chronic liver injury stimulates fibrogenesis in response to the imbalance between ECM accumulation and fibrosis resolution. Liver disease that induces fibrogenesis is associated with multiple risk factors like hepatitis infection, schistosomiasis, alcohol, certain drugs, toxicants and emerging aetiology like diabetes and obesity. The activation of hepatic stellate cells (HSCs), whose function is to generate and accumulate ECM, is a pivotal event in liver fibrosis. Simultaneously, HSCs selectively promote regulatory T-cells (Tregs) in an interleukin-2-dependent pattern that displays a dual relationship. On the one hand, Tregs can protect HSCs from NK cell attack, while on the other hand, they demonstrate an inhibitory effect on HSCs. This paper reviews the dual role of Tregs in liver fibrogenesis which includes its promotion of immunosuppression, as well as its activation of fibrosis. In particular, the balance between Tregs and the Th17 cell population, which produce interleukin (IL)-17 and IL-22, is explored to demonstrate their key role in maintaining homoeostasis and immunoregulation. The contradictory roles of Tregs in liver fibrosis in different immune microenvironments and molecular pathways need to be better understood if they are to be deployed to manage this disease.

CD4+ T cell activation and inflammation in NASH-related fibrosis

Liver fibrosis is a common pathological feature of end stage liver failure, a severe life-threatening disease worldwide. Nonalcoholic fatty liver disease (NAFLD), especially its more severe form with steatohepatitis (NASH), results from obesity, type 2 diabetes and metabolic syndrome and becomes a leading cause of liver fibrosis. Genetic factor, lipid overload/toxicity, oxidative stress and inflammation have all been implicated in the development and progression of NASH. Both innate immune response and adaptive immunity contribute to NASH-associated inflammation. Innate immunity may cause inflammation and subsequently fibrosis via danger-associated molecular patterns. Increasing evidence indicates that T cell-mediated adaptive immunity also provokes inflammation and fibrosis in NASH via cytotoxicity, cytokines and other proinflammatory and profibrotic mediators. Recently, the single-cell transcriptome profiling has revealed that the populations of CD4+ T cells, CD8+ T cells, γδ T cells, and TEMs are expanded in the liver with NASH. The activation of T cells requires antigen presentation from professional antigen-presenting cells (APCs), including macrophages, dendritic cells, and B-cells. However, since hepatocytes express MHCII molecules and costimulators, they may also act as an atypical APC to promote T cell activation. Additionally, the phenotypic switch of hepatocytes to proinflammatory cells in NASH contributes to the development of inflammation. In this review, we focus on T cells and in particular CD4+ T cells and discuss the role of different subsets of CD4+ T cells including Th1, Th2, Th17, Th22, and Treg in NASH-related liver inflammation and fibrosis.

Recurrence After Resection of Pancreatic Cancer: Can Radiomics Predict Patients at Greatest Risk of Liver Metastasis?

BACKGROUND

Liver metastasis (LM) after pancreatic ductal adenocarcinoma (PDAC) resection is common but difficult to predict and has grave prognosis. We combined preoperative clinicopathological variables and quantitative analysis of computed tomography (CT) imaging to predict early LM.

METHODS

We retrospectively evaluated patients with PDAC submitted to resection between 2005 and 2014 and identified clinicopathological variables associated with early LM. We performed liver radiomic analysis on preoperative contrast-enhanced CT scans and developed a logistic regression classifier to predict early LM (< 6 months).

RESULTS

In 688 resected PDAC patients, there were 516 recurrences (75%). The cumulative incidence of LM at 5 years was 41%, and patients who developed LM first (n = 194) had the lowest 1-year overall survival (OS) (34%), compared with 322 patients who developed extrahepatic recurrence first (61%). Independent predictors of time to LM included poor tumor differentiation (hazard ratio (HR) = 2.30; P < 0.001), large tumor size (HR = 1.17 per 2-cm increase; P = 0.048), lymphovascular invasion (HR = 1.50; P = 0.015), and liver Fibrosis-4 score (HR = 0.89 per 1-unit increase; P = 0.029) on multivariate analysis. A model using radiomic variables that reflect hepatic parenchymal heterogeneity identified patients at risk for early LM with an area under the receiver operating characteristic curve (AUC) of 0.71; the performance of the model was improved by incorporating preoperative clinicopathological variables (tumor size and differentiation status; AUC = 0.74, negative predictive value (NPV) = 0.86).

CONCLUSIONS

We confirm the adverse survival impact of early LM after resection of PDAC. We further show that a model using radiomic data from preoperative imaging combined with tumor-related variables has great potential for identifying patients at high risk for LM and may help guide treatment selection.

Crucial role of T cells in NAFLD-related disease: A review and prospect

Nonalcoholic fatty liver disease (NAFLD) includes a series of hepatic manifestations, starting with liver steatosis and potentially evolving towards nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis or even hepatocellular carcinoma (HCC). Its incidence is increasing worldwide. Several factors including metabolic dysfunction, oxidative stress, lipotoxicity contribute to the liver inflammation. Several immune cell-mediated inflammatory processes are involved in NAFLD in which T cells play a crucial part in the progression of the disease. In this review, we focus on the role of different subsets of both conventional and unconventional T cells in pathogenesis of NAFLD. Factors regarding inflammation and potential therapeutic approaches targeting immune cells in NASH are also discussed.

Cross-talk between hepatic stellate cells and T lymphocytes in liver fibrosis

BACKGROUND

Fibrosis results from inflammation and healing following injury. The imbalance between extracellular matrix (ECM) secretion and degradation leads to the ECM accumulation and liver fibrosis. This process is regulated by immune cells. T lymphocytes, including alpha beta (αβ) T cells, which have adaptive immune functions, and gamma delta (γδ) T cells, which have innate immune functions, are considered regulators of liver fibrosis. This review aimed to present the current understanding of the cross-talk between T lymphocytes and hepatic stellate cells (HSCs), which are the key cells in liver fibrosis.

DATA SOURCES

The keywords "liver fibrosis", "immune", and "T cells" were used to retrieve articles published in PubMed database before January 31, 2020.

RESULTS

The ratio of CD8+ (suppressor) T cells to CD4+ (helper) T cells is significantly higher in the liver than in the peripheral blood. T cells secrete a series of cytokines and chemokines to regulate the inflammation in the liver and the activation of HSCs to influence the course of liver fibrosis. In addition, HSCs also regulate the differentiation and proliferation of T cells.

CONCLUSIONS

The cross-talk between T cells and HSCs regulates liver fibrosis progression. The elucidation of this communication process will help us to understand the pathological process of liver fibrosis.

Retrospective analysis of T-lymphocyte subsets and cytokines in malignant obstructive jaundice before and after external and internal biliary drainage

Objective

To study changes in T lymphocyte subsets, cytokines, and liver enzymes in patients with malignant obstructive jaundice (MOJ) before and after external biliary drainage (percutaneous transhepatic cholangiography drainage, PTCD) and internal biliary drainage (percutaneous transhepatic insertion of biliary stents, PTIBS).

Methods

MOJ patients undergoing PTCD (n = 44) and PTIBS (n = 38) at our hospital were enrolled in the study from January 2017 until December 2019. Peripheral blood total bilirubin (TBIL), direct bilirubin (DBIL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), CD3⁺%, CD4⁺%, CD4⁺/CD8⁺ ratio, interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α were measured before and 1 week after biliary drainage.

Results

There was no significant difference in any parameter between the two groups before biliary drainage. TBIL, DBIL, AST and ALT following PTCD were significantly lower than before PTCD. By contrast, CD3⁺%, CD4⁺%, CD4⁺/CD8⁺ ratio, IL-2, IL-6 and TNF-α showed no significant difference before and 1 week after PTCD. TBIL, DBIL, AST, ALT, IL-6 and TNF-α were significantly lower following PTIBS than before PTIBS. CD3⁺%, CD4⁺%, CD4⁺/CD8⁺ ratio and IL-2 were significantly higher following PTIBS than before PTIBS.

Conclusion

Both PTCD and PTIBS were effective for treatment of MOJ, but PTIBS was more beneficial for recovery of immune function.

Novel Mechanisms for Resolution of Liver Inflammation: Therapeutic Implications

Traditional concepts have classically viewed resolution of inflammation as a passive process yet insight into the pathways by which inflammation is resolved has challenged this idea. Resolution has been revealed as a highly dynamic and active event that is essential to counteract the dysregulated inflammatory response that drives diverse disease states. Abrogation of the hepatic inflammatory response through the stimulation of proresolving mechanisms represents a new paradigm in the setting of chronic inflammatory-driven liver diseases. Elucidation of the role of different cells of the innate and adaptive immune system has highlighted the interplay between them as an important orchestrator of liver repair. A finely tuned interaction between neutrophils and macrophages has risen as revolutionary mechanism that drives the restoration of hepatic function and architecture. Specialized proresolving mediators have also been shown to act as stop signals of the inflammatory response and promote resolution as well as tissue regeneration. In this review, we discuss the discovery and understanding of the mechanisms by which inflammation is resolved and highlight novel proresolving pathways that represent promising therapeutic strategies.

An insight into the mechanism and molecular basis of dysfunctional immune response involved in cholestasis

Cholestasis is one of the most common clinical symptom of liver diseases. If patients do not receive effective treatment, cholestasis can evolve into liver fibrosis, cirrhosis and ultimately liver failure requiring liver transplantation. Currently, only ursodeoxycholic acid, obeticholic acid and bezafibrate are FDA-approved drugs, thereby requiring a breakthrough in new mechanisms and therapeutic development. Inflammation is one of the common complications of cholestasis. Hepatic accumulation of toxic hydrophobic bile acids is a highly immunogenic process involving both resident and immigrating immune cells. And the resulting inflammation may further aggravate hepatocyte injury. Though, great investigations have been made in the immune responses during cholestasis, the relationship between immune responses and cholestasis remains unclear. Moreover, scarce reviews summarize the immune responses during cholestasis and the efficacy of therapies on immune response. The main purpose of this paper is to review the existing literature on dysfunctional immune response during cholestasis and the effect of treatment on immune response which may provide an insight for researchers and drug development.

The T Cell Receptor Immune Repertoire Protects the Liver From Reconsitution

Aberrant immune cell infiltrates and microcircumstances represent characteristic features of liver fibrosis. In this study, we profiled the transcriptomes of intrahepatic CD45⁺ immune cells, from mice, using single-cell RNA sequencing (scRNA-seq) technology to understand the landscape of intrahepatic immune cells during the pathogenesis of fibrosis. Analysis of approximately 10,000 single-cell transcriptomes revealed an increase in dendritic cells (DCs), macrophages, and neutrophils and a decrease in T and natural killer T (NKT) cells. In addition, we report changes in the transcriptomes of diverse immune cell types, implying a deteriorating intrahepatic immune microcircumstance. Furthermore, we uncovered a novel fibrosis-associated CD8 T (Ccl5⁺, Ccl4⁺) and CD4 T (mt-Co1⁺) cell subpopulation, which infiltrates fibrotic liver and is characterized by abnormal activation or inactivation as well as a TCR decline. The results from scRNA-seq and bulk immune repertoire sequencing (IR-seq) revealed an obvious decline in T cell receptor (TCR) clonotypes combined with shrinking VJ and VDJ segment usage, as well as lower complementarity-determining region 3 (CDR3) amino acid (AA) diversity from fibrotic liver. Interestingly, a deficiency of TCR IR (Tcrb^KO mice) led to a deterioration of liver fibrosis, coupled with activation of hepatic stellate cells (HSCs) induced by the upregulation of macrophage and γδ T cell distribution in fibrotic Tcrb^KO livers. Our findings reveal the landscape and dynamics of single immune cells in liver fibrosis, and clarify the protective role of TCR IR in response to chronic liver injury.

Foxp3+ Regulatory T Cells Inhibit CCl4-Induced Liver Inflammation and Fibrosis by Regulating Tissue Cellular Immunity

Foxp3+ regulatory T (Treg) cells are pivotal in maintaining immunological self-tolerance and tissue homeostasis; however, it remains unclear how tissue Treg cells respond to liver injury and regulate chronic inflammation, which can cause liver fibrosis. We report here that hepatic Treg cells play a critical role in preventing liver pathology by suppressing inflammatory cellular immunity that can promote liver damage and fibrosis. Chronic liver inflammation induced by injections of carbon tetrachloride (CCl₄) led to preferential expansion of hepatic Treg cells that prevented liver fibrosis. In contrast, depletion of Treg cells in the CCl₄-induced liver fibrosis model exacerbated the severity of liver pathology. Treg depletion unleashed tissue cellular immunity and drove the activation and expansion of the pro-fibrotic IL-4-producing T helper 2 cells, as well as CCR2^high Ly-6C^high inflammatory monocytes/macrophages in the inflamed liver. Although Treg expression of amphiregulin plays a key role in tissue remodeling and repair in various inflammation models, amphiregulin from hepatic Treg cells, the largest producer among liver immune cells, was dispensable for maintaining liver homeostasis and preventing liver fibrosis during CCl₄-induced chronic inflammation. Our results indicate that Treg cells control chronic liver inflammation and fibrosis by regulating the aberrant activation and functions of immune effector cells. Harnessing Treg functions, which effectively regulate tissue cellular immunity, may be a therapeutic strategy for preventing and treating liver fibrosis.

The Roles of Immune Cells in the Pathogenesis of Fibrosis

Tissue injury and inflammatory response trigger the development of fibrosis in various diseases. It has been recognized that both innate and adaptive immune cells are important players with multifaceted functions in fibrogenesis. The activated immune cells produce various cytokines, modulate the differentiation and functions of myofibroblasts via diverse molecular mechanisms, and regulate fibrotic development. The immune cells exhibit differential functions during different stages of fibrotic diseases. In this review, we summarized recent advances in understanding the roles of immune cells in regulating fibrotic development and immune-based therapies in different disorders and discuss the underlying molecular mechanisms with a focus on mTOR and JAK-STAT signaling pathways.

The liver fibrosis niche: Novel insights into the interplay between fibrosis-composing mesenchymal cells, immune cells, endothelial cells, and extracellular matrix

Liver fibrosis is a hepatic wound-healing response caused by chronic liver diseases that include viral hepatitis, alcoholic liver disease, non-alcoholic steatohepatitis, and cholestatic liver disease. Liver fibrosis eventually progresses to cirrhosis that is histologically characterized by an abnormal liver architecture that includes distortion of liver parenchyma, formation of regenerative nodules, and a massive accumulation of extracellular matrix (ECM). Despite intensive investigations into the underlying mechanisms of liver fibrosis, developments of anti-fibrotic therapies for liver fibrosis are still unsatisfactory. Recent novel experimental approaches, such as single-cell RNA sequencing and proteomics, have revealed the heterogeneity of ECM-producing cells (mesenchymal cells) and ECM-regulating cells (immune cells and endothelial cells). These approaches have accelerated the identification of fibrosis-specific subpopulations among these cell types. The ECM also consists of heterogenous components. Their production, degradation, deposition, and remodeling are dynamically regulated in liver fibrosis, further affecting the functions of cells responsible for fibrosis. These cellular and ECM elements cooperatively form a unique microenvironment: a fibrotic niche. Understanding the complex interplay between these elements could lead to a better understanding of underlying fibrosis mechanisms and to the development of effective therapies.

Inflammation and Cell Death During Cholestasis: The Evolving Role of Bile Acids

Cholestasis results in blockage of bile flow whether the point of obstruction occurs extrahepatically or intrahepatically. Bile acids are a primary constituent of bile, and thus one of the primary outcomes is acute retention of bile acids in hepatocytes. Bile acids are normally secreted into the biliary tracts and then released into the small bowel before recirculating back to the liver. Retention of bile acids has long been hypothesized to be a primary cause of the associated liver injury that occurs during acute or chronic cholestasis. Despite this, a surge of papers in the last decade have reported a primary role for inflammation in the pathophysiology of cholestatic liver injury. Furthermore, it has increasingly been recognized that both the constituency of individual bile acids that make up the greater pool, as well as their conjugation status, is intimately involved in their toxicity, and this varies between species. Finally, the role of bile acids in drug-induced cholestatic liver injury remains an area of increasing interest. The purpose of this review is to critically evaluate current proposed mechanisms of cholestatic liver injury, with a focus on the evolving role of bile acids in cell death and inflammation.

Clinical significance of the immune cell landscape in hepatocellular carcinoma patients with different degrees of fibrosis

Background

The major causes of morbidity and mortality of patients with chronic liver disease are liver fibrosis and cirrhosis. Previous studies have been concerned with immune dysfunction in the pathogenesis of cirrhosis progress. However, the potential molecular mechanism of how the liver's fibrotic state favors tumor progression is still unclear. We attempted to reveal deviations of the immune cell landscape between various liver tissues and identify key biomarkers associated with patients' outcomes.

Method

CIBERSORT was used for estimating the proportions of immune cells in various liver tissues. Comparative studies were carried out by Kruskal-Wallis test and Wilcoxon test. For survival analyses, the Cox proportional hazard regression model, Kaplan-Meier estimates, and log-rank test were used.

Results

Significantly different adaptive and innate immune cell types were selected, including T cells, plasma cells, and resting mast cells. Meanwhile, the immune cell landscapes in The Cancer Genome Atlas' (TCGA) hepatocellular carcinoma (HCC) patients with different degrees of fibrosis were also calculated. Comparative studies and survival analysis were carried out. Resting mast cell and activated NK cells in HCC patients with fibrosis was significantly lower than that in other HCC patients without fibrosis. Then, the potential genes involved in immune cells and significantly associated with patients' outcome were identified. These genes may be potential novel checkpoints for immunotherapy, including PVRIG related to NK resting/activated cells and T cell CD8+ infiltration which was recently targeted in breast cancer. Furthermore, Pearson correlation coefficient analysis suggested that PVRIG is significantly positively related to other checkpoint molecules and Teff gene signatures.

Conclusions

Alternative treatments, including immunotherapies, are necessary and urgent for HCC. Although checkpoint inhibitors that block CTLA-4 and PD-1 have improved cancer immunotherapies, targeting additional checkpoint receptors may be required to broaden patient response to immunotherapy. Our studies may find possible ways to select novel targets and improve immunotherapy efficacy by disrupting their function and promoting immune infiltration in advanced HCC patients with higher fibrosis and even cirrhosis.

Human Amnion Epithelial Cell Therapy for Chronic Liver Disease

Liver fibrosis is a common consequence of chronic liver disease. Over time, liver fibrosis can develop into liver cirrhosis. Current therapies for liver fibrosis are limited, and liver transplant is the only curative therapy for patients who progress to end-stage disease. A potential approach to treat chronic liver disease with increasing interest is cell-based therapy. Among the multiple cell types which have been proposed for therapeutic uses, human amnion epithelial cells and amniotic fluid-derived mesenchymal cells are promising. These cells are highly abundant, and their use poses no ethical concern. Furthermore, they exert potent anti-inflammatory and antifibrotic effects in animal models of liver injury. This review highlights the therapeutic characteristics and discusses how human amnion epithelial cells can be utilised as a therapeutic tool for chronic liver disease.

HITM-SIR: phase Ib trial of intraarterial chimeric antigen receptor T-cell therapy and selective internal radiation therapy for CEA+ liver metastases

Effective chimeric antigen receptor-modified T-cell (CAR-T) therapy for liver metastases (LM) will require innovative solutions to ensure efficient delivery and minimization of systemic toxicity. We previously demonstrated the safety of CAR-T hepatic artery infusions (HAI). We subsequently conducted the phase 1b HITM-SIR trial, in which six patients (pts) with CEA⁺ LM received anti-CEA CAR-T HAIs and selective internal radiation therapy (SIRT). The primary endpoint was safety with secondary assessments of biologic activity. Enrolled pts had a mean LM size of 6.4 cm, 4 pts had >10 LM, and pts received an average of two lines of prior systemic therapy. No grade 4 or 5 toxicities were observed, and there were no instances of severe cytokine-release syndrome (CRS) or neurotoxicity. The mean transduction efficiency was 60.4%. Following CAR-T HAI, reduced levels of GM-CSF-R, IDO, and PD-L1 were detected in LM, and serum CEA levels were stable or decreased in all subjects. Median survival time was 8 months (mean 11, range 4-31). Anti-CEA CAR-T HAI with subsequent SIRT was well tolerated, and biologic responses were demonstrated following failure of conventional therapy. HAI of CAR-T was once again confirmed not to be associated with severe CRS or neurotoxicity.

Sortilin 1 Loss-of-Function Protects Against Cholestatic Liver Injury by Attenuating Hepatic Bile Acid Accumulation in Bile Duct Ligated Mice

Sortilin 1 (Sort1) is an intracellular trafficking receptor that mediates protein sorting in the endocytic or secretory pathways. Recent studies revealed a role of Sort1 in the regulation of cholesterol and bile acid (BA) metabolism. This study further investigated the role of Sort1 in modulating BA detoxification and cholestatic liver injury in bile duct ligated mice. We found that Sort1 knockout (KO) mice had attenuated liver injury 24 h after bile duct ligation (BDL), which was mainly attributed to less bile infarct formation. Sham-operated Sort1 KO mice had about 20% larger BA pool size than sham-operated wildtype (WT) mice, but 24 h after BDL Sort1 KO mice had significantly attenuated hepatic BA accumulation and smaller BA pool size. After 14 days BDL, Sort1 KO mice showed significantly lower hepatic BA concentration and reduced expression of inflammatory and fibrotic marker genes, but similar degree of liver fibrosis compared with WT mice. Unbiased quantitative proteomics revealed that Sort1 KO mice had increased hepatic BA sulfotransferase 2A1, but unaltered phase-I BA metabolizing cytochrome P450s or phase-III BA efflux transporters. Consistently, Sort1 KO mice showed elevated plasma sulfated taurocholate after BDL. Finally, we found that liver Sort1 was repressed after BDL, which may be due to BA activation of farnesoid x receptor. In conclusion, we report a role of Sort1 in the regulation of hepatic BA detoxification and cholestatic liver injury in mice. The mechanisms underlying increased hepatic BA elimination in Sort1 KO mice after BDL require further investigation.

Dual effect of T helper cell 17 (Th17) and regulatory T cell (Treg) in liver pathological process: From occurrence to end stage of disease

Liver disease is a complicated pathological status with acute or chronic progressions, causing a series of damages to liver and massive burden to public health and society. Th17 and Treg, two subsets of CD4⁺ T helper cells, seem to keep a subtle balance in the maintenance of organic immune homeostasis including liver. The dysfunction of Th17/Treg balance in liver has been proved associated with hepatic injury and disease. Herein, we summarized the research advance of Th17 and Treg cells in different phenotypes of liver diseases in the past decade. It is known to all that hepatic diseases start from stimulations or infections like virus, autoimmune, alcohol and so on in the early stage, which would cause inflammation. With the disease consistently existed, severe outcomes like cirrhosis and hepatocellular carcinoma appear finally. In conclusion, it is found that Th17 and Treg cells serve as an important role in the immune response imbalance of liver diseases from the beginning to the end stage. However, the effect of these two subsets of CD4⁺ T helper cells is not a stereotype. Pathological role which exacerbates the disease and protective character which inhibits damage to liver are co-existed in the effect of Th17 and Treg cells. Still, more studies should be carried out to enrich the understandings of liver disease and Th17/Treg immune balance in the future.

Measuring Apoptosis and Necrosis in Cholestatic Liver Injury

Cholestasis can be induced by obstruction of bile ducts or intrahepatic toxicity of drugs and chemicals. However, the mode of cell death during cholestasis, i.e., apoptosis or necrosis, has been controversial. There are fundamental reasons for the controversies, both of which are discussed here, namely the design of experiments and the use of parameters with limited specificity for a certain mode of cell death. Based on the assumption that cholestatic liver injury is caused by accumulation of bile acids, rodent (mainly rat) hepatocytes have been exposed to hydrophobic, glycine-conjugated bile acids, which resulted in apoptotic cell death. The problems with this experimental design are that in rodents bile acids are predominantly taurine conjugated and rodent hepatocytes are never exposed to these levels of glycine-conjugated bile acids. In contrast, taurine-conjugated bile acids trigger inflammatory gene activation in rodent hepatocytes and a necro-inflammatory injury in vivo. On the other hand, human hepatocytes are more resistant to glycine-conjugated bile acids and die by necrosis when exposed to high biliary levels of these bile acids. In this chapter, we describe multiple assays including the caspase activity assay, which is specific for apoptosis, and the general cell death assays alanine aminotransferase or lactate dehydrogenase activities in cell culture medium or plasma. An increase in these enzyme activities without caspase activity indicates necrotic cell death. Thus, both the experimental design and the selection of cell death parameters are critical for the relevance of the experiments for the human pathophysiology.

Changes in preoperative endoscopic and percutaneous bile drainage in patients with periampullary cancer undergoing pancreaticoduodenectomy in Ontario: effect on clinical practice of a randomized trial

Background

In 2010, a multicentre randomized controlled trial reported increased postoperative complications in pancreaticoduodenectomy (pde) patients undergoing preoperative biliary decompression (pbd). We evaluated the effect of that publication on rates of pbd at the population level.

Methods

This retrospective observational cohort study identified patients undergoing pde for malignancy, 2005-2013, linking them with administrative health care databases covering medical services for a population of 13.5 million. Patients undergoing pbd within 6 weeks before their surgery were identified using physician billing codes and were divided into those undergoing pde before and after article publication, with a 6-month washout period. Chi-square tests were used to compare rates of pbd.

Results

Of 1997 pde patients identified, 963 underwent surgery before article publication, and 911, after (123 during the washout period). The rate of pbd was 47.5% before publication, and 41.6% after (p = 0.01). The lowest pbd rates occurred immediately after publication, in 2010 and 2011. Similar results were observed when the cohort was restricted to patients seen preoperatively by a gastroenterologist (n = 1412).

Conclusions

Rates of pbd have declined a small, but significant, amount after randomized trial publication. Persistence of pbd might relate to suboptimal knowledge translation, the role of pbd in diagnosis of periampullary malignancy, and treatment of complications (cholangitis, severe hyperbilirubinemia) or anticipation of delay from diagnosis to surgery. The nadir in pbd rates after article publication and the subsequent rise suggest an element of transience in the effect of article publication on clinical practice. Further investigation into the reasons for persistent pbd is needed.

Effect of preoperative biliary stenting on post-operative infectious complications in pancreaticoduodenectomy

Backgrounds/Aims

The impact of pre-operative biliary stenting (PBS) in patients undergoing pancreaticoduodenectomy on post-operative infectious complications is unclear. Therefore, the purpose of this study is to investigate the relationship between PBS and post-operative infectious complications, to determine the effect of PBS on bile bacteriology, and to correlate the bacteriology of bile and bacteria cultured from post-operative infectious complications in our institute.

Methods

Details of 51 patients undergoing pancreaticoduodenectomy January 2011-April 2015 were reviewed. Of 51 patients, 30 patients underwent pre-operative biliary stenting (PBS group) and 21 patients underwent pancreaticoduodenectomy without pre-operative biliary stenting. Post-operative infectious complications were compared between the two groups.

Results

Overall post-operative infectious complication rate was 77% and 67% in the PBS and non-PBS groups respectively. Wound infection was the main infectious complication followed by intraabdominal abscess. The rate of wound infection doubled in the PBS group (50% vs 28%). There was slight increase in incidence of intraabdominal abscess in PBS group (53% vs 46%). 80% of PBS patients had positive intraoperative bile culture as compared to 20% in non-PBS group.

Conclusions

Preoperative biliary drainage prior to pancreaticoduodenectomy increases risk of developing post-operative wound infections and intra-abdominal collections.

Th17/Treg imbalance is an indicator of liver cirrhosis process and a risk factor for HCC occurrence in HBV patients

OBJECTIVE

To determine the impact of T helper 17 cell (Th17)/regulatory T cell (Treg) ratio imbalance on the process and prognosis of hepatitis B virus (HBV)-related liver cirrhosis.

METHODS

Patients with HBV who refused to accept any therapy from were recruited from 2009 to 2014 and followed-up to August 2016. Based on a liver stiffness measurement (LSM), the patients were divided into a low LSM group and a high LSM group. After propensity score matching, 150 patients were included. The peripheral blood of all subjects was tested using a flow cytometer to measure the Th17 and Treg cell frequencies and the Th17/Treg ratio. Spearman rank correlation, log-rank test, Cox regression model, and receiver operating characteristic (ROC) curves were applied to analyze the correlation between the Th17/Treg ratio and LSM level and the risk factors of HCC occurrence and to predict the Th17/Treg ratio for the LSM level.

RESULTS

Th17 and Treg cell frequencies and the Th17/Treg ratio were significantly different between the low and high LSM groups. The Th17/Treg ratio showed a strong positive association with LSM level (r=0.631, P<0.01). Furthermore, the Th17/Treg ratio was an independent factor influencing the HCC occurrence, which was tested using a Cox regression model. The area under the ROC curve of the Th17/Treg ratio for predicting LSM level was 0.783 (95% CI 0.705-0.861).

CONCLUSION

Th17/Treg ratio imbalance is an indicator of the liver cirrhosis process and a risk factor for HCC occurrence in patients infected with HBV.

Gallbladder Cancer Presenting with Jaundice: Uniformly Fatal or Still Potentially Curable?

BACKGROUND

Jaundice as a presenting symptom of gallbladder cancer has traditionally been considered to be a sign of advanced disease, inoperability, and poor outcome. However, recent studies have demonstrated that a small subset of these patients can undergo resection with curative intent.

METHODS

Patients with gallbladder cancer managed surgically from 2000 to 2014 in 10 US academic institutions were stratified based on the presence of jaundice at presentation (defined as bilirubin ≥4 mg/ml or requiring preoperative biliary drainage). Perioperative morbidity, mortality, and overall survival were compared between jaundiced and non-jaundiced patients.

RESULTS

Of 400 gallbladder cancer patients with available preoperative data, 108 (27%) presented with jaundice while 292 (73%) did not. The fraction of patients who eventually underwent curative-intent resection was much lower in the presence of jaundice (n = 33, 30%) than not (n = 218, 75%; P < 0.001). Jaundiced patients experienced higher perioperative morbidity (69 vs. 38%; P = 0.002), including a much higher need for reoperation (12 vs. 1%; P = 0.003). However, 90-day mortality (6.5 vs. 3.6%; P = 0.35) was not significantly higher. Overall survival after resection was worse in jaundiced patients (median 14 vs. 32 months; P < 0.001). Further subgroup analysis within the jaundiced patients revealed a more favorable survival after resection in the presence of low CA19-9 < 50 (median 40 vs. 12 months; P = 0.003) and in the absence of lymphovascular invasion (40 vs. 14 months; P = 0.014).

CONCLUSION

Jaundice is a powerful preoperative clinical sign of inoperability and poor outcome among gallbladder cancer patients. However, some of these patients may still achieve long-term survival after resection, especially when preoperative CA19-9 levels are low and no lymphovascular invasion is noted pathologically.

Context- and Tissue-Specific Regulation of Immunity and Tolerance by Regulatory T Cells

The immune system has evolved to defend the organism against an almost infinite number of pathogens in a locally confined and antigen-specific manner while at the same time preserving tolerance to harmless antigens and self. Regulatory T (Treg) cells essentially contribute to an immunoregulatory network preventing excessive immune responses and immunopathology. There is emerging evidence that Treg cells not only operate in secondary lymphoid tissue but also regulate immune responses directly at the site of inflammation. Hence, the classification of Treg cells might need to be further extended by Treg cell subsets that are functionally and phenotypically polarized by their residency. In this review, we discuss recent findings on these tissue-resident Treg cell subsets and how these cells may operate in a tissue- and context-dependent manner.

Adverse outcome pathway development from protein alkylation to liver fibrosis

In modern toxicology, substantial efforts are undertaken to develop alternative solutions for in vivo toxicity testing. The adverse outcome pathway (AOP) concept could facilitate knowledge-based safety assessment of chemicals that does not rely exclusively on in vivo toxicity testing. The construction of an AOP is based on understanding toxicological processes at different levels of biological organisation. Here, we present the developed AOP for liver fibrosis and demonstrate a linkage between hepatic injury caused by chemical protein alkylation and the formation of liver fibrosis, supported by coherent and consistent scientific data. This long-term process, in which inflammation, tissue destruction, and repair occur simultaneously, results from the complex interplay between various hepatic cell types, receptors, and signalling pathways. Due to the complexity of the process, an adequate liver fibrosis cell model for in vitro evaluation of a chemical's fibrogenic potential is not yet available. Liver fibrosis poses an important human health issue that is also relevant for regulatory purposes. An AOP described with enough mechanistic detail might support chemical risk assessment by indicating early markers for downstream events and thus facilitating the development of an in vitro testing strategy. With this work, we demonstrate how the AOP framework can support the assembly and coherent display of distributed mechanistic information from the literature to support the use of alternative approaches for prediction of toxicity. This AOP was developed according to the guidance document on developing and assessing AOPs and its supplement, the users' handbook, issued by the Organisation for Economic Co-operation and Development.

Negative short-term impact of intraoperative biliary lavage in patients with hepatolithiasis

AIM: To evaluate short-term outcomes following intraoperative biliary lavage for hepatolithiasis.

METHODS: A total of 932 patients who were admitted to the West China Medical Center of Sichuan University between January 2010 and January 2014 and underwent bile duct exploration and lithotomy were retrospectively included in our study. The patients were divided into the lavage group and the control group. Related pre-, intra-, and postoperative factors were recorded, analyzed, and compared between the two groups in order to verify the effects of biliary lavage on the short-term outcome of patients with hepatolithiasis.

RESULTS: Amongst the patients who were included, 678 patients with hepatolithiasis were included in the lavage group, and the other 254 patients were enrolled in the control group. Data analyses revealed that preoperative baseline and related intraoperative variables were not significantly different. However, patients who underwent intraoperative biliary lavage had prolonged postoperative hospital stays (6.67 d vs 7.82 d, P = 0.024), higher hospitalization fees (RMB 28437.1 vs RMB 32264.2, P = 0.043), higher positive rates of bacterial cultures from blood (13.3% vs 25.8%, P = 0.001) and bile (23.6% vs 40.7%, P = 0.001) samples, and increased usage of advanced antibiotics (26.3% vs 38.2%, P = 0.001). In addition, in the lavage group, more patients had fever (> 37.5 °C, 81.4% vs 91.1%, P = 0.001) and hyperthermia (> 38.5°C，39.7% vs 54.9%, P = 0.001), and higher white blood cell counts within 7 d after the operation compared to the control group.

CONCLUSION: Intraoperative biliary lavage might increase the risk of postoperative infection, while not significantly increasing gallstone removal rate.

Malignant Biliary Obstruction: Evidence for Best Practice

What should be done next? Is the stricture benign? Is it resectable? Should I place a stent? Which one? These are some of the questions one ponders when dealing with biliary strictures. In resectable cases, ongoing questions remain as to whether the biliary tree should be drained prior to surgery. In palliative cases, the relief of obstruction remains the main goal. Options for palliative therapy include surgical bypass, percutaneous drainage, and stenting or endoscopic stenting (transpapillary or via an endoscopic ultrasound approach). This review gathers scientific foundations behind these interventions. For operable cases, preoperative biliary drainage should not be performed unless there is evidence of cholangitis, there is delay in surgical intervention, or intense jaundice is present. For inoperable cases, transpapillary stenting after sphincterotomy is preferable over percutaneous drainage. The use of plastic stents (PS) has no benefit over Self-Expandable Metallic Stents (SEMS). In case transpapillary drainage is not possible, Endoscopic Ultrasonography- (EUS-) guided drainage is still an option over percutaneous means. There is no significant difference between the types of SEMS and its indication should be individualized.

Endoscopic stenting for inoperable malignant biliary obstruction: A systematic review and meta-analysis

AIM: To analyze through meta-analyses the benefits of two types of stents in the inoperable malignant biliary obstruction.

METHODS: A systematic review of randomized clinical trials (RCT) was conducted, with the last update on March 2015, using EMBASE, CINAHL (EBSCO), MEDLINE, LILACS/CENTRAL (BVS), SCOPUS, CAPES (Brazil), and gray literature. Information of the selected studies was extracted in sight of six outcomes: primarily regarding dysfunction, complication and re-intervention rates; and secondarily costs, survival, and patency time. The data about characteristics of trial participants, inclusion and exclusion criteria and types of stents were also extracted. The bias was mainly assessed through the JADAD scale. This meta-analysis was registered in the PROSPERO database by the number CRD42014015078. The analysis of the absolute risk of the outcomes was performed using the software RevMan, by computing risk differences (RD) of dichotomous variables and mean differences (MD) of continuous variables. Data on RD and MD for each primary outcome were calculated using the Mantel-Haenszel test and inconsistency was qualified and reported in χ² and the Higgins method (I²). Sensitivity analysis was performed when heterogeneity was higher than 50%, a subsequent assay was done and other findings were compiled. Student’s t-test was used for the comparison of weighted arithmetic means regarding secondary outcomes.

RESULTS: Initial searching identified 3660 studies; 3539 were excluded through title, repetition, and/or abstract, while 121 studies were fully assessed and were excluded mainly because they did not compare self-expanding metal stents (SEMS) and plastic stents (PS), leading to thirteen RCT selected, with 13 articles and 1133 subjects meta-analyzed. The mean age was 69.5 years old, that were affected mostly by bile duct (proximal) and pancreatic tumors (distal). The preferred SEMS diameter used was the 10 mm (30 Fr) and the preferred PS diameter used was 10 Fr. In the meta-analysis, SEMS had lower overall stent dysfunction compared to PS (21.6% vs 46.8%, P < 0.00001) and fewer re-interventions (21.6% vs 56.6%, P < 0.00001), with no difference in complications (13.7% vs 15.9%, P = 0.16). In the secondary analysis, the mean survival rate was higher in the SEMS group (182 d vs 150 d, P < 0.0001), with a higher patency period (250 d vs 124 d, P < 0.0001) and a lower cost per patient (4193.98 vs 4728.65 Euros, P < 0.0985).

CONCLUSION: SEMS are associated with lower stent dysfunction, lower re-intervention rates, better survival, and higher patency time. Complications and costs showed no difference.

Migration of splenic lymphocytes promotes liver fibrosis through modification of T helper cytokine balance in mice

BACKGROUND

Sustained liver injury causes liver fibrosis and eventually cirrhosis. Understanding the pathophysiological mechanisms of liver fibrosis and interventions in the fibrotic process is crucial for improving the prognosis of patients with chronic liver diseases. Although studies have shown that splenectomy suppresses liver fibrosis, the mechanism by which this occurs is poorly understood. The present study focuses on the immunological functions of the spleen to investigate its role in liver fibrosis.

METHODS

BALB/c and severe combined immunodeficiency (SCID) mice underwent splenectomies or sham operations prior to induction of liver fibrosis with carbon tetrachloride or thioacetamide.

RESULTS

Sirius red staining and hydroxyproline assays showed that splenectomy suppressed liver fibrogenesis in BALB/c mice. Reverse transcription PCR analysis of T helper type 1 (Th1) and T helper type 2 (Th2) cytokines demonstrated that splenectomy shifted the Th1/Th2 balance in the liver towards Th1 dominance. In SCID mice, the inhibitory effect on liver fibrosis was abrogated. The number of CD4(+) T helper lymphocytes in the spleen decreased after liver injury. Green fluorescent protein positive (GFP(+)) splenocytes were transplanted into the spleens of syngeneic wild-type mice to trace their destination after fibrosis induction. GFP(+)CD4(+) lymphocytes appeared in the liver after induction of fibrosis, and flow cytometry revealed the vast majority of them were Th2 lymphocytes. Transfer of splenocytes via the portal vein into syngeneic splenectomized mice cancelled the suppressive effect of splenectomy on liver fibrosis.

CONCLUSIONS

The present study demonstrated that Th2-dominant splenic lymphocytes migrate into the liver and promote liver fibrosis by shifting the cytokine balance towards Th2 dominance. Splenectomy suppresses the progression of fibrosis at least partly by restoring the Th1/Th2 balance.

Phase I Hepatic Immunotherapy for Metastases Study of Intra-Arterial Chimeric Antigen Receptor-Modified T-cell Therapy for CEA+ Liver Metastases

PURPOSE

Chimeric antigen receptor-modified T cells (CAR-T) have demonstrated encouraging results in early-phase clinical trials. Successful adaptation of CAR-T technology for CEA-expressing adenocarcinoma liver metastases, a major cause of death in patients with gastrointestinal cancers, has yet to be achieved. We sought to test intrahepatic delivery of anti-CEA CAR-T through percutaneous hepatic artery infusions (HAIs).

EXPERIMENTAL DESIGN

We conducted a phase I trial to test HAI of CAR-T in patients with CEA(+) liver metastases. Six patients completed the protocol, and 3 received anti-CEA CAR-T HAIs alone in dose-escalation fashion (10(8), 10(9), and 10(10) cells). We treated an additional 3 patients with the maximum planned CAR-T HAI dose (10(10) cells × 3) along with systemic IL2 support.

RESULTS

Four patients had more than 10 liver metastases, and patients received a mean of 2.5 lines of conventional systemic therapy before enrollment. No patient suffered a grade 3 or 4 adverse event related to the CAR-T HAIs. One patient remains alive with stable disease at 23 months following CAR-T HAI, and 5 patients died of progressive disease. Among the patients in the cohort that received systemic IL2 support, CEA levels decreased 37% (range, 19%-48%) from baseline. Biopsies demonstrated an increase in liver metastasis necrosis or fibrosis in 4 of 6 patients. Elevated serum IFNγ levels correlated with IL2 administration and CEA decreases.

CONCLUSIONS

We have demonstrated the safety of anti-CEA CAR-T HAIs with encouraging signals of clinical activity in a heavily pretreated population with large tumor burdens. Further clinical testing of CAR-T HAIs for liver metastases is warranted.

Depletion of Foxp3+ Regulatory T Cells Promotes Profibrogenic Milieu of Cholestasis-Induced Liver Injury

BACKGROUND

Accumulating evidence suggests that Foxp3+ regulatory T (Treg) cells act as inhibitory mediators of inflammation; however, the in vivo mechanism underlying this protection remains elusive in liver diseases.

AIMS

To clarify the in vivo role of Foxp3+ Treg cells in liver fibrosis, we used the DEREG mouse, which expresses the diphtheria toxin receptor under control of the Foxp3 promoter, allowing for specific deletion of Foxp3+ Treg cells.

METHODS

Bile duct ligation-induced liver injury and fibrosis were assessed by histopathology, fibrogenic gene expression, and measurement of cytokine and chemokine levels.

RESULTS

Depletion of Foxp3+ Treg cells enhanced Th17 cell response as demonstrated by the increase of IL-17+ cells and related gene expressions including Il17f, Il17ra, and Rorgt in the fibrotic livers of DEREG mice. Of note, infiltration of CD8+ T cells and Cd8 gene expression was significantly increased in the livers of DEREG mice. Consistent with increased IL-17+ and CD8+ T cell responses, DEREG mice generated higher levels of inflammatory cytokines (TNF-α, IL-6, and IL-12p70) and chemokines (MCP-1, MIP-1α, and RANTES). These results were concordant with severity of liver fibrosis and hepatic enzyme levels (ALT and ALP).

CONCLUSIONS

The present findings demonstrate that Foxp3+ Treg cells inhibit the profibrogenic inflammatory milieu through suppression of pro-fibrogenic CD8+ and IL-17+ T cells.

Treg-enriched CD4+ T cells attenuate collagen synthesis in keloid fibroblasts

Keloid is an inflammatory and fibrotic disease with an unknown pathogenesis. Regulatory T cells (Tregs) of CD4+ lineage can suppress other effector CD4+ T cells and modulate the immune response. A relative decrease in the number of Tregs may be involved in the pathogenesis of inflammatory and fibrotic diseases. We therefore investigated the number of Tregs in keloids using immunohistochemistry and examined the interaction between Tregs and keloid fibroblasts (KFs) using a coculture system. It was found that the ratio of Tregs/CD4+ T cells was lower compared with that in other common inflammatory skin conditions. In addition, Treg-enriched CD4+ T cells reduced collagen synthesis by KFs. Our findings suggest that a local imbalance of Tregs contributes to the development of keloids and that correction of this imbalance might represent a novel therapeutic approach to keloid fibrosis.

Liver fibrosis and repair: immune regulation of wound healing in a solid organ

Fibrosis is a highly conserved and co-ordinated protective response to tissue injury. The interaction of multiple pathways, molecules and systems determines whether fibrosis is self-limiting and homeostatic, or whether it is uncontrolled and excessive. Immune cells have been identified as key players in this fibrotic cascade, with the capacity to exert either injury-inducing or repair-promoting effects. A multi-organ approach was recently suggested to identify the core and regulatory pathways in fibrosis, with the aim of integrating the wealth of information emerging from basic fibrosis research. In this Review, we focus on recent advances in liver fibrosis research as a paradigm for wound healing in solid organs and the role of the immune system in regulating and balancing this response.

Jaundice: an important, poorly recognized risk factor for diminished survival in patients with adenocarcinoma of the head of the pancreas

OBJECTIVES

Jaundice impairs cellular immunity, an important defence against the dissemination of cancer. Jaundice is a common mode of presentation in pancreatic head adenocarcinoma. The purpose of this study was to determine whether there is an association between preoperative jaundice and survival in patients who have undergone resection of such tumours.

METHODS

Thirty possible survival risk factors were evaluated in a database of over 400 resected patients. Univariate analysis was used to determine odds ratio for death. All factors for which a P-value of <0.30 was obtained were entered into a multivariate analysis using the Cox model with backward selection.

RESULTS

Preoperative jaundice, age, positive node status, poor differentiation and lymphatic invasion were significant indicators of poor outcome in multivariate analysis. Absence of jaundice was a highly favourable prognostic factor. Interaction emerged between jaundice and nodal status. The benefit conferred by the absence of jaundice was restricted to patients in whom negative node status was present. Five-year overall survival in this group was 66%. Jaundiced patients who underwent preoperative stenting had a survival advantage.

CONCLUSIONS

Preoperative jaundice is a negative risk factor in adenocarcinoma of the pancreas. Additional studies are required to determine the exact mechanism for this effect.

Regulatory T cells in nonlymphoid tissues

Both Foxp3(+)CD4(+) regulatory T cells (Treg cells) and local immune responses in nonlymphoid tissues have long been recognized as important elements of a well-orchestrated immune system, but only recently have these two fields of study begun to intersect. There is growing evidence that Treg cells are present in various nonlymphoid tissues in health and disease, that they have a unique phenotype and that their functions go beyond the classical modulation of immune responses. Thus, tissue Treg cells might add yet another level to classification of the Treg cell compartment into functional and/or phenotypic subtypes. In this Review, we summarize recent findings in this new field, discussing knowns and unknowns about the origin, phenotype, function and memory of nonlymphoid tissue-resident Treg cells.

Fibrosis and subsequent cytopenias are associated with basic fibroblast growth factor-deficient pluripotent mesenchymal stromal cells in large granular lymphocyte leukemia

Cytopenias occur frequently in systemic lupus erythematosus, rheumatoid arthritis, Felty's syndrome, and large granular lymphocyte (LGL) leukemia, but the bone marrow microenvironment has not been systematically studied. In LGL leukemia (n = 24), retrospective analysis of bone marrow (BM) histopathology revealed severe fibrosis in 15 of 24 patients (63%) in association with the presence of cytopenias, occurrence of autoimmune diseases, and splenomegaly, but was undetectable in control cases with B cell malignancies (n = 11). Fibrosis severity correlated with T cell LGL cell numbers in the BM, but not in the periphery, suggesting deregulation is limited to the BM microenvironment. To identify fibrosis-initiating populations, primary mesenchymal stromal cultures (MSCs) from patients were characterized and found to display proliferation kinetics and overabundant collagen deposition, but displayed normal telomere lengths and osteoblastogenic, chondrogenic, and adipogenic differentiation potentials. To determine the effect of fibrosis on healthy hematopoietic progenitor cells (HPCs), bioartificial matrixes from rat tail or purified human collagen were found to suppress HPC differentiation and proliferation. The ability of patient MSCs to support healthy HSC proliferation was significantly impaired, but could be rescued with collagenase pretreatment. Clustering analysis confirmed the undifferentiated state of patient MSCs, and pathway analysis revealed an inverse relationship between cell division and profibrotic ontologies associated with reduced basic fibroblast growth factor production, which was confirmed by ELISA. Reconstitution with exogenous basic fibroblast growth factor normalized patient MSC proliferation, collagen deposition, and HPC supportive function, suggesting LGL BM infiltration and secondary accumulation of MSC-derived collagen is responsible for hematopoietic failure in autoimmune-associated cytopenias in LGL leukemia.

Differential regulation of hepatic organic cation transporter 1, organic anion-transporting polypeptide 1a4, bile-salt export pump, and multidrug resistance-associated protein 2 transporter expression in lymphocyte-deficient mice associates with interleukin-6 production

Cholestasis results from interrupted bile flow and is associated with immune-mediated liver diseases. It is unclear how inflammation contributes to cholestasis. The aim of this study was to determine whether T and B cells contribute to hepatic transporter expression under basal and inflammatory conditions. C57BL/6J wild-type mice or strains lacking T, B, or both T and B cells were exposed to lipopolysaccharide (LPS) or saline, and livers were collected 16 hours later. Branched DNA signal amplification was used to assess mRNA levels of organic anion-transporting polypeptides (Oatp) 1a1, 1a4, and 1b2; organic cation transporter (Oct) 1; canalicular bile-salt export pump (Bsep); multidrug resistance-associated proteins (Mrp) 2 and 3; and sodium-taurocholate cotransporting polypeptide (Ntcp). Real-time polymerase chain reaction analysis was used to correlate changes of transporter expression with interleukin-1b (IL-1b), IL-6, IL-17A, IL-17F, tumor necrosis factor-α (TNF-α), and interferon-γ expression in the liver. LPS treatment inhibited Bsep and Oct1 mRNA expression, and this was abrogated with a loss of T cells, but not B cells. In addition, the absence of T cells increased Mrp2 mRNA expression, whereas B cell deficiency attenuated Oatp1a4 mRNA in LPS-treated mice. Oatp1a1, Oatp1b2, Ntcp, and Mrp3 were largely unaffected by T or B cell deficiency. Lymphocyte deficiency altered basal and inflammatory IL-6, but not TNF-α or IL-1b, mRNA expression. Taken together, these data implicate lymphocytes as regulators of basal and inflammatory hepatic transporter expression and suggest that IL-6 signaling may play a critical role.